1 /* -*- linux-c -*- 2 * Cypress USB Thermometer driver 3 * 4 * Copyright (c) 2004 Erik Rigtorp <erkki@linux.nu> <erik@rigtorp.com> 5 * 6 * This driver works with Elektor magazine USB Interface as published in 7 * issue #291. It should also work with the original starter kit/demo board 8 * from Cypress. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License as 12 * published by the Free Software Foundation, version 2. 13 * 14 */ 15 16 17 #include <linux/kernel.h> 18 #include <linux/errno.h> 19 #include <linux/slab.h> 20 #include <linux/module.h> 21 #include <linux/usb.h> 22 23 #define DRIVER_VERSION "v1.0" 24 #define DRIVER_AUTHOR "Erik Rigtorp" 25 #define DRIVER_DESC "Cypress USB Thermometer driver" 26 27 #define USB_SKEL_VENDOR_ID 0x04b4 28 #define USB_SKEL_PRODUCT_ID 0x0002 29 30 static const struct usb_device_id id_table[] = { 31 { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) }, 32 { } 33 }; 34 MODULE_DEVICE_TABLE (usb, id_table); 35 36 /* Structure to hold all of our device specific stuff */ 37 struct usb_cytherm { 38 struct usb_device *udev; /* save off the usb device pointer */ 39 struct usb_interface *interface; /* the interface for this device */ 40 int brightness; 41 }; 42 43 44 /* local function prototypes */ 45 static int cytherm_probe(struct usb_interface *interface, 46 const struct usb_device_id *id); 47 static void cytherm_disconnect(struct usb_interface *interface); 48 49 50 /* usb specific object needed to register this driver with the usb subsystem */ 51 static struct usb_driver cytherm_driver = { 52 .name = "cytherm", 53 .probe = cytherm_probe, 54 .disconnect = cytherm_disconnect, 55 .id_table = id_table, 56 }; 57 58 /* Vendor requests */ 59 /* They all operate on one byte at a time */ 60 #define PING 0x00 61 #define READ_ROM 0x01 /* Reads form ROM, value = address */ 62 #define READ_RAM 0x02 /* Reads form RAM, value = address */ 63 #define WRITE_RAM 0x03 /* Write to RAM, value = address, index = data */ 64 #define READ_PORT 0x04 /* Reads from port, value = address */ 65 #define WRITE_PORT 0x05 /* Write to port, value = address, index = data */ 66 67 68 /* Send a vendor command to device */ 69 static int vendor_command(struct usb_device *dev, unsigned char request, 70 unsigned char value, unsigned char index, 71 void *buf, int size) 72 { 73 return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), 74 request, 75 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER, 76 value, 77 index, buf, size, 78 USB_CTRL_GET_TIMEOUT); 79 } 80 81 82 83 #define BRIGHTNESS 0x2c /* RAM location for brightness value */ 84 #define BRIGHTNESS_SEM 0x2b /* RAM location for brightness semaphore */ 85 86 static ssize_t show_brightness(struct device *dev, struct device_attribute *attr, char *buf) 87 { 88 struct usb_interface *intf = to_usb_interface(dev); 89 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 90 91 return sprintf(buf, "%i", cytherm->brightness); 92 } 93 94 static ssize_t set_brightness(struct device *dev, struct device_attribute *attr, const char *buf, 95 size_t count) 96 { 97 struct usb_interface *intf = to_usb_interface(dev); 98 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 99 100 unsigned char *buffer; 101 int retval; 102 103 buffer = kmalloc(8, GFP_KERNEL); 104 if (!buffer) 105 return 0; 106 107 cytherm->brightness = simple_strtoul(buf, NULL, 10); 108 109 if (cytherm->brightness > 0xFF) 110 cytherm->brightness = 0xFF; 111 else if (cytherm->brightness < 0) 112 cytherm->brightness = 0; 113 114 /* Set brightness */ 115 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS, 116 cytherm->brightness, buffer, 8); 117 if (retval) 118 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 119 /* Inform µC that we have changed the brightness setting */ 120 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM, 121 0x01, buffer, 8); 122 if (retval) 123 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 124 125 kfree(buffer); 126 127 return count; 128 } 129 130 static DEVICE_ATTR(brightness, S_IRUGO | S_IWUSR | S_IWGRP, 131 show_brightness, set_brightness); 132 133 134 #define TEMP 0x33 /* RAM location for temperature */ 135 #define SIGN 0x34 /* RAM location for temperature sign */ 136 137 static ssize_t show_temp(struct device *dev, struct device_attribute *attr, char *buf) 138 { 139 140 struct usb_interface *intf = to_usb_interface(dev); 141 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 142 143 int retval; 144 unsigned char *buffer; 145 146 int temp, sign; 147 148 buffer = kmalloc(8, GFP_KERNEL); 149 if (!buffer) 150 return 0; 151 152 /* read temperature */ 153 retval = vendor_command(cytherm->udev, READ_RAM, TEMP, 0, buffer, 8); 154 if (retval) 155 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 156 temp = buffer[1]; 157 158 /* read sign */ 159 retval = vendor_command(cytherm->udev, READ_RAM, SIGN, 0, buffer, 8); 160 if (retval) 161 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 162 sign = buffer[1]; 163 164 kfree(buffer); 165 166 return sprintf(buf, "%c%i.%i", sign ? '-' : '+', temp >> 1, 167 5*(temp - ((temp >> 1) << 1))); 168 } 169 170 171 static ssize_t set_temp(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 172 { 173 return count; 174 } 175 176 static DEVICE_ATTR(temp, S_IRUGO, show_temp, set_temp); 177 178 179 #define BUTTON 0x7a 180 181 static ssize_t show_button(struct device *dev, struct device_attribute *attr, char *buf) 182 { 183 184 struct usb_interface *intf = to_usb_interface(dev); 185 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 186 187 int retval; 188 unsigned char *buffer; 189 190 buffer = kmalloc(8, GFP_KERNEL); 191 if (!buffer) 192 return 0; 193 194 /* check button */ 195 retval = vendor_command(cytherm->udev, READ_RAM, BUTTON, 0, buffer, 8); 196 if (retval) 197 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 198 199 retval = buffer[1]; 200 201 kfree(buffer); 202 203 if (retval) 204 return sprintf(buf, "1"); 205 else 206 return sprintf(buf, "0"); 207 } 208 209 210 static ssize_t set_button(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 211 { 212 return count; 213 } 214 215 static DEVICE_ATTR(button, S_IRUGO, show_button, set_button); 216 217 218 static ssize_t show_port0(struct device *dev, struct device_attribute *attr, char *buf) 219 { 220 struct usb_interface *intf = to_usb_interface(dev); 221 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 222 223 int retval; 224 unsigned char *buffer; 225 226 buffer = kmalloc(8, GFP_KERNEL); 227 if (!buffer) 228 return 0; 229 230 retval = vendor_command(cytherm->udev, READ_PORT, 0, 0, buffer, 8); 231 if (retval) 232 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 233 234 retval = buffer[1]; 235 236 kfree(buffer); 237 238 return sprintf(buf, "%d", retval); 239 } 240 241 242 static ssize_t set_port0(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 243 { 244 struct usb_interface *intf = to_usb_interface(dev); 245 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 246 247 unsigned char *buffer; 248 int retval; 249 int tmp; 250 251 buffer = kmalloc(8, GFP_KERNEL); 252 if (!buffer) 253 return 0; 254 255 tmp = simple_strtoul(buf, NULL, 10); 256 257 if (tmp > 0xFF) 258 tmp = 0xFF; 259 else if (tmp < 0) 260 tmp = 0; 261 262 retval = vendor_command(cytherm->udev, WRITE_PORT, 0, 263 tmp, buffer, 8); 264 if (retval) 265 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 266 267 kfree(buffer); 268 269 return count; 270 } 271 272 static DEVICE_ATTR(port0, S_IRUGO | S_IWUSR | S_IWGRP, show_port0, set_port0); 273 274 static ssize_t show_port1(struct device *dev, struct device_attribute *attr, char *buf) 275 { 276 struct usb_interface *intf = to_usb_interface(dev); 277 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 278 279 int retval; 280 unsigned char *buffer; 281 282 buffer = kmalloc(8, GFP_KERNEL); 283 if (!buffer) 284 return 0; 285 286 retval = vendor_command(cytherm->udev, READ_PORT, 1, 0, buffer, 8); 287 if (retval) 288 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 289 290 retval = buffer[1]; 291 292 kfree(buffer); 293 294 return sprintf(buf, "%d", retval); 295 } 296 297 298 static ssize_t set_port1(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 299 { 300 struct usb_interface *intf = to_usb_interface(dev); 301 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 302 303 unsigned char *buffer; 304 int retval; 305 int tmp; 306 307 buffer = kmalloc(8, GFP_KERNEL); 308 if (!buffer) 309 return 0; 310 311 tmp = simple_strtoul(buf, NULL, 10); 312 313 if (tmp > 0xFF) 314 tmp = 0xFF; 315 else if (tmp < 0) 316 tmp = 0; 317 318 retval = vendor_command(cytherm->udev, WRITE_PORT, 1, 319 tmp, buffer, 8); 320 if (retval) 321 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 322 323 kfree(buffer); 324 325 return count; 326 } 327 328 static DEVICE_ATTR(port1, S_IRUGO | S_IWUSR | S_IWGRP, show_port1, set_port1); 329 330 331 332 static int cytherm_probe(struct usb_interface *interface, 333 const struct usb_device_id *id) 334 { 335 struct usb_device *udev = interface_to_usbdev(interface); 336 struct usb_cytherm *dev = NULL; 337 int retval = -ENOMEM; 338 339 dev = kzalloc (sizeof(struct usb_cytherm), GFP_KERNEL); 340 if (!dev) 341 goto error_mem; 342 343 dev->udev = usb_get_dev(udev); 344 345 usb_set_intfdata (interface, dev); 346 347 dev->brightness = 0xFF; 348 349 retval = device_create_file(&interface->dev, &dev_attr_brightness); 350 if (retval) 351 goto error; 352 retval = device_create_file(&interface->dev, &dev_attr_temp); 353 if (retval) 354 goto error; 355 retval = device_create_file(&interface->dev, &dev_attr_button); 356 if (retval) 357 goto error; 358 retval = device_create_file(&interface->dev, &dev_attr_port0); 359 if (retval) 360 goto error; 361 retval = device_create_file(&interface->dev, &dev_attr_port1); 362 if (retval) 363 goto error; 364 365 dev_info (&interface->dev, 366 "Cypress thermometer device now attached\n"); 367 return 0; 368 error: 369 device_remove_file(&interface->dev, &dev_attr_brightness); 370 device_remove_file(&interface->dev, &dev_attr_temp); 371 device_remove_file(&interface->dev, &dev_attr_button); 372 device_remove_file(&interface->dev, &dev_attr_port0); 373 device_remove_file(&interface->dev, &dev_attr_port1); 374 usb_set_intfdata (interface, NULL); 375 usb_put_dev(dev->udev); 376 kfree(dev); 377 error_mem: 378 return retval; 379 } 380 381 static void cytherm_disconnect(struct usb_interface *interface) 382 { 383 struct usb_cytherm *dev; 384 385 dev = usb_get_intfdata (interface); 386 387 device_remove_file(&interface->dev, &dev_attr_brightness); 388 device_remove_file(&interface->dev, &dev_attr_temp); 389 device_remove_file(&interface->dev, &dev_attr_button); 390 device_remove_file(&interface->dev, &dev_attr_port0); 391 device_remove_file(&interface->dev, &dev_attr_port1); 392 393 /* first remove the files, then NULL the pointer */ 394 usb_set_intfdata (interface, NULL); 395 396 usb_put_dev(dev->udev); 397 398 kfree(dev); 399 400 dev_info(&interface->dev, "Cypress thermometer now disconnected\n"); 401 } 402 403 module_usb_driver(cytherm_driver); 404 405 MODULE_AUTHOR(DRIVER_AUTHOR); 406 MODULE_DESCRIPTION(DRIVER_DESC); 407 MODULE_LICENSE("GPL"); 408